Exceptional points in single open acoustic resonator due to symmetry breaking

Exceptional points (EPs) have been widely studied in quantum mechanics, condensed-matter physics, optics, and photonics. However, their potential in acoustics has only recently been recognized due to the rapid development of acoustic metamaterials. This paper proposes a method for achieving EP conditions in acoustic resonators by lowering their symmetry and enabling resonant-mode interaction. The formation of EPs is predicted through direct numerical simulation supported by coupled-mode theory and resonant state expansion. These findings have significant implications for the design and optimization of acoustic metamaterials for applications such as acoustic sensing and noise reduction.